Yarn heating system



Jan. 21, 1958 G; F, BE N 2,820,280

YARNl-IEA TING SYSTEM Filed Nov; 20, 1956 /0 9 2 .9 i? WWW WW INVENTOR ATTORNEYS United States Patent YARN HEATING SYSTEM George F. Benn, Greensboro, N. C., assignor to J. P. Stevens & Co., Inc., NewYork, N. Y., a corporation of Delaware Application November 20, 1956, Serial No. 623,462

Claims. (Cl. 28-62) This invention relates to heating systems which are adapted to use with equipment for processing synthetic yarns, particularly for imparting a so-called set to nylon yarns.

It is well-known that nylon will tend to maintain a condition, or position, in which it has been set by the applica tion of heat. This characteristic is utilized in many processes of yarn treatment, among which is the making of stretch yarn. There are several processes for making stretch yarns from nylon, but all employ a setting step. Following one of these processes, yarn is taken from a source of supply, twisted, set and untwisted. The twisting and untwisting is done by means of a false twister, and this permits the twisting, setting and untwisting to take place during straight line travel of the yarn. The setting is usually accomplished by passing the twisted yarn through a heated can. Electric elements have been used in the cans to provide the necessary heat. It has been particularly difiicult to accurately control the heat in the individual cans so that all yarns on a machine would receive uniform heat. Lack of uniformity in the process resulted in lack of uniformity in the finished yarns.

The object of the present invention is to provide a heating system for yarn processing apparatus which will be capable of delivering heat to a plurality of units at progressively increasing distances from the heat input point with the heat at all points being substantially uniform.

Another object of the invention is to provide such a system in which the heating medium is in constant motion and brought in contact with but one element to be heated before being reheated and recirculated.

A further object is to provide in such a system means to circulate the heating medium which will build up a predetermined pressure in the medium but will slip to avoid excessive pressures in the event of line blockage.

Other objects of the invention will become apparent from the following description of one practical embodiment of the invention when taken in conjunction with the drawings which accompany, and form part of, this specification.

In the drawings:

Figure 1 is a diagrammatic elevational view of a heating system constructed in accordance with the present invention;

Figure 2 is a top plan view of the structure shown in Figure 1;

Figure 3 is a vertical section through one of the heating elements and adjacent apparatus and is taken on the line 33 of Figure 1; and,

Figure 4 is a horizontal section taken on the line 4-4 of Figure 3.

In general, the invention contemplates the provision of a closed system for the circulation of a heating medium with means in the system for heating the medium as it circulates. More specifically, it includes means for carrying the medium to a plurality of elements to be heated with any given quantity of the medium contacting but one such element before being reheated.

Patented Jan. 21, 1958 2 e Referring to the drawings in detail, there is shown a heating system which is designed for use with the conventional two-bank twister frame which consists of upper and lower banks of twisters, each having a plurality of twisters. At each twister station,- yarn is brought from a cop and trained along a vertical path, the twister being positioned midway along this straight vertical path. The

treated yarn is then wound on a cop, spool or bobbin as desired in well-known manner. During its travel along the straight path to the twister head, the yarn is heated to set the twist.

The heating system shown includes a pair of horizontally positioned headers 1 and 2, arranged one above the other to extend the length of the twister banks. The two headers are connected at one end by a pipe 3, and an intake pipe 4 is coupled to the connecting pipe. The opposite ends of the headers are connected to return lines 5 and 6, which extend the length of the machine parallel to the headers and below them. U-bends 7 and 8 form the connections between the headers and return lines. It will be noted that the U-bends are of much smaller cross-section than the headers and return lines. These serve merely as bleed-off lines to prevent heating medium standing in the headers and causing temperature drops at the ends of the headers farthest from the intake.

Cans 9, through which the yarn passes for heating, are bridged across the headers and return lines by means of the pipes 10 and 11. The cans are provided with central tubes 12 which extend beyond the ends of the cans and provide a passageway for the yarn. Each can forms an individual bridge, taking heating medium from its header and passing it to the return line. No heating medium from the cans ever returns to the headers, and heating medium from the headers never contacts more than one yarn tube. This is important, as each yarn tube acts as a chimney and heat losses up the tubes are bound to occur.

The return lines 5 and 6 are connected together by pipe line 13, which is coupled to one end of a heater 14. The heater may be of any suitable type. The opposite end of the heater is joined by a pipe 15 to a propellor type pump 16, which is also connected to intake line 4.

It will be seen that the structure disclosed provides a closed system through which a heating medium may be circulated. It is proposed to use oil as the heating medium and to circulate it through the system at approximately two hundred gallons per minute at a pressure of substantially five pounds. This will provide rapid movement of the oil at relatively low pressure to reduce danger of burst pipe and spraying of hot oil. A propellor pump will provide this rate of circulation and, if stoppage in the line should occur, will slip without building up excessive pressures.

The oil will be heated to about four hundred fifty degrees and will be maintained at that temperature by passing it through the heater each cycle of circulation.

This system is adapted to use with conventional twisters, and the cans 9 can be placed in alignment with the usual paths of yarn travel. The oil will move quickly, none of the oil contacts more than one can before reheating, and the U-bends 7 and 8 prevent stagnation in the headers and keep a swift flow of hot oil even to the cans farthest removed from the heater. With this arrangement, there will be no appreciable temperature differences at any of the cans, irrespective of their positions along the header.

While in the above one practical embodiment of the invention has been disclosed, it will be apparent that the details of structure which have been described and shown are merely by way of illustration and the system may take other forms without departing from the scope of the invention as defined in the appended claims.

What is claimed is:

1. A heating system for treating yarns moving along straight parallel paths on a textile machine comprising, a header extending across and adjacent all of said paths, a return line parallel to and spaced from said header, a line interconnecting said header and return line and having a heater and pump serially connected therein, and a housing surrounding each of said yarn paths and having connections to said header and said return line.

2. In a heating system as claimed in claim 1, said line interconnecting said header and return lines being connected to one end of said header and one end of said return line, and a second line interconnecting the opposite ends of said header and return lines, whereby a con-v tinuous closed fluid flow path is provided thru said header, return line, heater and pump.

3. In a heating system as claimed in claim 1, said pump being of a type to provide maximum flow with limited pressure.

4. In a heating system as claimed in claim 1, said housing comprising a closed end cylinder and an open end tube positioned coaxially of said cylinder and extending completely through said cylinder.

5. A heater system for treating yarns moving along straight parallel paths on a textile machine comprising, a header, a return line, a line interconnecting one end of said header with one end of said return line and having a heater and pump serially connected therein, a bleeder connection between the opposite ends of said header and return line, and a housing surrounding each of said yarn paths and bridged across said header and return line.

References Cited in the file of this patent UNITED STATES PATENTS 1,531,343 Naito Mar. 31, 1925 2,199,411 Lewis May 7, 1940 2,803,105 Stoddard et al Aug. 20, 1957 FOREIGN PATENTS 175,965 Austria Sept. 10, 1953 

